At a rooftop bar in Berlin on May 29th, the glitterati of Germany’s startup scene toasted a new arrival. Silicon Valley Bank, a commercial lender which counts as customers half of American startups that went public in 2017, has just opened an office in the country. “They are doing unique, cool things here,” gushed Greg Becker, the bank’s boss. One of his first German clients is Lilium Aviation, whose electric flying taxis have mastered the tricky combination of a drone-like vertical take-off and forward jet propulsion.

Silicon Valley Bank arrives as a new breed of German startups is gaining altitude. At first e-commerce firms dominated the scene, often by copying ideas from abroad. Rocket Internet, an early success, went further, cloning American e-commerce models in other countries, too. Rocket and Zalando, a fashion e-tailer, did initial public offerings in 2014. After that only two big stockmarket debuts followed, of HelloFresh (which sells meal-kits) and Delivery Hero (a...